The present invention relates to a method of scavenging free radicals by incorporating orange extract into a composition.
The deleterious effects of free radicals are, in many cases, known but are continually being investigated. For example, it is believed that one of the causes of the deterioration of skin over time is the formation of free radicals within the elements forming the skin such as the fibers, cells and enzymes. The formation of free radicals may be caused, in part, by the action of external radiation of sunlight. The free radicals thus formed may attack the skin elements through a chain reaction that continues as long as the free radical exists, i.e., as long as the free radical does not combine with something (typically called a scavenger or inhibitor) that produces a stable molecule. The adverse action of these free radicals at the cutaneous integument level may cause destruction of cell DNA and an erosion of the connective tissues (collagen and elastin). Thus, the skin looks more aged.
As a result, substances that interrupt or inhibit the formation of free radicals during the free radical chain reaction are continually being sought. At the present, well known scavengers (also referred to as inhibitors or antioxidants, and as used in the following specification and appended claims should be considered synonymous with scavenger) include phenols, aromatic amines, sulfur compounds, raw seed oils, wheat germ oil, tocopherols, and gums. It is also believed that phosphoric acid, citric acid, and ascorbic acid have their own scavenging activity or enhance the activity of the known scavengers mentioned above.
Thus, French Demande 2,597,337-A2 describes a cosmetic to slow down the aging process by attacking free radicals. The cosmetic includes a first water soluble active ingredient, which may include a source of vitamin C such as from acerola cherry extract, and a second fat soluble ingredient, which includes free radical scavengers such as vitamin E.
While the above French Demande describes the use of acerola cherry extract, it is particularly with respect to the presence of vitamin C, known to be present in relatively high amounts when compared to other natural sources of vitamin C. Likewise, Japanese Laid-open applications 2-200610 and 70-61915 describe that an extract obtained from fruits of acerola may be incorporated into cosmetics. Those applications teach that the acerola cherry contain vitamin C or ascorbic acid and application no. 2-200610 describes the extract as containing at least 1% L-ascorbic acid and it is the presence of the L-ascorbic acid that provides the desired whitening effect. This is not surprising since, it is well known that L-ascorbic acid provides a whitening effect.
There is, however, no appreciation that an orange extract, which is substantially free of vitamin C, has free radical scavenging activity. The present inventors have now found that an orange extract exhibits free radical scavenging activity and, as a result may find particular application in the preparation of pharmaceutical, food and agricultural compositions, and more particularly in cosmetics for external skin application. Thus, the ability of the orange extract used in the present invention to scavenge free radicals is surprising and unexpected.